Thursday, June 2, 2016

A synchronous generator is rated at 10MVA, 11kV, 0.85 p.f., 50Hz. What is the significance of 0.85 p.f.?

A)Load of p.f. more than 0.85 cannot be met
B)The prime-mover power rating is 8.5 MW 
C)It does not have any significance
D)Load of p.f. less than 0.85 cannot be met


If the effect of earth is taken into account, then the capacitance of line to ground

A)Remains unaltered 
B)Increases 
C)Decreases
D)Becomes infinite


What is the effect of an integral controller on the type and order of the system?

A)Increases the type by one and increases the order by one
B)Decreases the type by one and increases the order by one
C)Decreases the type by one and decreases the order by one
D)Increases the type by one and decreases the order by one


The fault which occurs rarely in practice and is the most severe and imposes more heavy duty on the circuit breaker is

A)Line to line fault
B)Single line to ground fault 
C)Symmetrical fault 
D)Double line to ground fault


The temperature independent polarization is

A)Orientation polarization 
B)Space discharge polarization
C)Electronic polarization
D)Space charge polarization


If the gain of a transfer function is increased then the

A)Phase crossover frequency is decreased 
B)Gain crossover frequency is decreased 
C)Phase crossover frequency is increased 
D)Gain crossover frequency is increased


The insulators used in guy cables are

A)Stay insulators
B)Shackle insulators
C)Disc insulators
D)Pin insulators


A derivative controller

A)Improves transient stability
B)Improves steady state stability
C)Improves both the steady state and transient stability
D)Does not affect system stability 


Under force-voltage analogy, viscous friction co-efficient is analogous to

A)Reciprocal of inductance 
B)Charge 
C)Resistance
D)Reciprocal of capacitance


The armature reaction of a synchronous generator under short-circuit condition is

A)Both demagnetising and cross-magnetising
B)Magnetising 
C)Cross-magnetising
D)Demagnetising


A vibration galvanometer is tuned

A)by changing its damping constant
B)by attaching weight to the vibrating coil 
C)by changing length and tension of vibrating coil
D)by changing its damping factor


Thermal relays are commonly used in

A)Generator protection
B)Motor starters
C)Transformer protection 
D)Feeder protection


Which one of the following alphanumeric code is used on punched paper cards?

A)8-bit EBCDIC 
B)7-bit Selectric 
C)7-bit BCDIC
D)12-bit Hollerith


In DMA operation, data transfer takes place between

A)Different CPUs 
B)I/O and memory
C)I/O and CPU 
D)Memory and CPU


In a transmission line there is a flow of zero sequence current when

A)Double line to ground fault
B)Line to line fault
C)Three phase fault 
D)There is an occurrence of over voltage on line due to a charged cloud


For circulating current mode operation of dual converter

A)2nd bridge is gated after a small time interval of the 1st one is gated
B)Only one bridge is gated at a time 
C)1st bridge is turned off before the 2nd bridge is gated
D)Both the bridges are gated simultaneously 


The instruction queue in 8086 CPU is

A)Of random access type 
B)Of FIFO type
C)Of infinite queue
D)Of LIFO type


Johnson noise is

A)caused by thermal agitation of free electrons carrying current 
B)shot noise which results from random emission of electrons across a p-n junction
C)noise of an electromagnetic origin that is radiated into the circuit
D)noise carried into the circuit through conductors


A program counter is a storage register for

A)Location of instruction in memory
B)Binary code for the operation to be performed
C)Location of data in memory
D)Address of next instruction to be executed


In a chopper circuit, the switching device is turned off at regular intervals by adopting

A)A combination of forced and natural commutation 
B)Forced commutation 
C)Either forced or natural commutation
D)Natural commutation


The positive swing of the output signal in a transistor circuit starts clipping when Q-point of the circuit moves towards the

A)Centre of the load line 
B)Centre of the supply lineS
C)Saturation point 
D)Cut-off point


The 8085 microprocessor responds to the presence of an interrupt

A)as soon as the TRAP pin becomes high 
B)by checking the TRAP pin for high status at the end of the execution of each instruction
C)by checking the TRAP pin for high status at regular intervals
D)by checking the TRAP pin for high status at the end of each instruction fetch